Electromagnetic hammer drill



Sept. 26, 1967 G. s. JONES, JR

ELECTROMAGNETI C HAMMER DRILL 2 Sheets-Sheet l Filed Feb. 23, 1965INVENTOR GROVER S. JONES JR.

k/ vr/f BY Mu j, /IML/b ATTORNEY Sept. 26, 1967 G. s. JONES, JR

ELECTROMAGNETIC HAMMER DRILL 2 sheets-sheet 2 Filed Feb. 23, 1965 FIG.4.

FIG. 3

GROVER S. JONES JR.

ATTORNEY United States Patent 3,343,611 ELECTRGMAGNETIC HAMMER DRILLGrover Stephen Jones, Jr., 251 Fallsbrook Road, Timonium, Md. 21093Filed Feb. 23, 1965, Ser. No. 434,203 9 Claims. (Cl. 173-117) Thisinvention relates to hammer drills and it is more particularly concernedwith electromagnetic drills that utilize an external source of energy inthe form of electrical energy to furnish a substantial part of the workinput.

An object of the invention is the provision of improvements inelectromagnetic drills that render them highly etlicient in actual useas compared to conventional drills.

Another object is the provision `of improvements which result in asturdy as well as an efcient drilling tool.

A still further object is the provision of improvements which render thetool capable of being operated in different ways to meet particularconditions encountered in practice.

These objects and still further objects will be apparent from thefollowing description as explained hereinafter in conjunction with adetailed description of an embodiment of the invention illustrated inthe accompanying drawing.

In the drawing:

FIG. 1 is a side elevational view of a conventional drilling rig, partlybroken away, in combination with a drill comprising an embodiment of theinvention.

FIGS. 2a and 2b together comprise a general longitudinal sectional viewof the embodiment of FIG. 1 on a larger scale as it would appear inactual operation inside an earth well being drilled.

FIGS. 3, 4 and 5 are diagrammatic views of the embodiment in differentcyclic positions to illustrate the operation thereof.

Referring with more particularity to the drawing, there is shown in FIG.1 a conventional drilling rig 11 mounted on an ordinary truck 12. Therig 11 comprises a powered Winch 13 about which one end of a hoistingcable 14 is wound. The cable passes from the winch 13 over a stationarysheave 15, then under a sheave 16 mounted at the end of an oscillatingbeam 17, and thence to the top of a derrick 18 where it passes over asheave 19 and then vertically downward to the drill device 20. The drilldevice conventionally operates in casing sections 21, these sectionsbeing connected together serially and lowered into the ground vas thedrilling progresses.

The embodiment comprises an upper cylindrical header section 22 to whichthe free end of the hoisting cable 14 is attached by conventional means.

The header section 22 has an axial bore 23 therethrough which isenlarged at the lower end to provide a counterbore 24 adapted to receiveand retain an electrical switch 25 having an actuator pin 26 normallyspring biased downwardly into the counterbore.

The lower end of the header section 22 has an eX- ten'or annular recess27 adapted to fit inside the upper end of a tubular section 28 andsecured thereto by shrink fitting or any other suitable means.

Within the tubular section 28 there is disposed a solenoid comprising alongitudinal hollow electromagnetic coil 29, the upper end of which isin abutting engagement with the bottom of the header section 22 and thelower end in abutting engagement with a shoulder 30 formed by arestricted portion 31 at the bottom of tubular section 28.

The solenoid also comprises a solid cylindrical armature 32 adapted toreciprocate longitudinally within this coil 29. The upper end of thearmature 32 is adapted "ice to strike the switch pin 26 on its upwardmovement and retract it against its spring force that normally urges itto a protracted position. The armature 32 comprises the upper section ofa hammer member 33 that has a central enlarged portion 34 and a lowerrecessed portion 35. The central portion is slidably mounted in atubular section 36, the upper end of which is connected by shrinkfitting or otherwise to a reduced section 37 of the tubular section 28.The lower portion 35 has a slightly enlarged bottom tip 38 whichslidably engages a cylindrical bushing 39 press tted inside the tubularsection 36 and supported against the end of the upper nipple 40 of aconnector 41.

The electromagnetic coil 29 is electrically connected to the switch 25by electrical wires 42 in a passageway 43 therebetween in the headersection 22. The switch is connected to a conventional source of variabledirect electrical energy (not shown) by lead wires 44 passing throughthe bore 23.

The coil spring 45 is disposed about the section.32 between the centralportion 34 and the bottom of the tubular section 28. A secondcounteracting coil spring 46 is disposed about the lower portion 35between the bottom of the central portion 34 and the top of the bushing39. Suitable end pressure rings 47, 48, and 49, 50 are provided forthese springs, as shown in the drawing.

The lower nipple 51 of the connector 41 is attached to the upper end ofa tubular section S2 by shrink fitting or otherwise. A transmission bar53 is axially disposed in the section 52, an enlarged lower portion 54being slidably engaged with an end wall opening 55 and the upper endhaving an enlarged head 56 in slidable contact with the connector 41.The bottom 57 of the lower nipple 51 is restricted in slidable contactwith the transmission bar 53 and forming an annular neck 58. The upperend of an accordion seal 59 of rubber, nylon, other suitable exiblewater impervious material, is secured to the neck 58 by a collar clamp60 and the lower end is secured to a waist section 61 of the bar 54 bymeans of a clamping ring 62.

At the bottom of the drill, is the drill bit 63. It has a shank 64slidably disposed at the bottom of a tubular section 65. The upper endof the tubular section 65 has a restricted portion 66 forming adownwardly facing annular shoulder 67. The shank 64 has an upperrestricted portion 68 which forms an upwardly facing annular shoulder69. Between the shoulders 67 and 69 there is disposed a coil spring 70about the shank portion 68. Pressure rings 71 and 72 are disposed at therespective ends of the spring. The upper end of the shank portion 68extends upwardly through and above an aperture 73 of the restrictedportion 66. The upper end of the shank portion 68 is capped by an anvilhead 74. The head 74 is reciprocably mounted in a tubular section 75,the lower end of which is connected to the recessed upper end 76 of thebottom tubular section and the upper end to the bottom of the tubularsection 52.

The device is placed in a vertical position with the cutting edge of thebit in contact with the surface 77 of the medium to be drilled. This maybe done by means of the cable 14 from the rig 11 or of any conventionalchurn drilling apparatus.

The lowermost spring should be of such strength within its elastic limitthat when the weight of the drill or of a prescribed portion thereof isallowed to push downward against the bit 63, the tubular sectionsconnected together as a unit balance in the position indicated in FIGURE4 with the upper end of the armature 32 applying an upward push againstthe linger 26. When the pin 26 is urged upwardly by the upper end of thearmature 32, an electrical circuit is completed to pass direct electriccurrent through the electromagnetic coil 29, thereby creating a magneticux upwardly of sutiicient strength to urge the hammer member 33 upwardlyinto the position depicted in FIGURE 5. When the pin 26 is pushedupwardly beyond a prescribed distance, such as illustrated in FIGURE 5,current ceases to pass through the coil 29, magnetic flux ceases toexist, and the hammer 33 descends rapidly under the action of itssupporting springs to impact with the anvil head 74 (position shown inFIGURE 4). The release of pressure on the finger 26 subsequentlytriggers the flow of current through the coil 29 and a magnetic ilux isset up for relifting the hammer 33 to the position indicated in FIGURE5. Thus, a rhythmic series of impacts is delivered to the bit anvil 74and the result is a highly effective drilling action.

. The weight of the co-joined tubular sections should exceed that of thehammer 32 sufliciently so that the hammer performs most of the motionunder the action of the magnetic ux. Allowance, however, may be made forthe upper shoulder 78 of the anvil head chamber to impact with the anvilhead 74 at the instant when the hammer 33 is in its uppermost positionunder the action of the magnetic flux.

In order to assure turning of the bit the drill as a whole is liftedperiodically for repositioning by the rig, the cable being initiallytwisted to provide this effect. A conventional ratchet device (notshown) may also be utilized between the bit assembly and the casingassembly to assure more controlled rotation.

By varying the strength and distribution of direct curdelivery of thecurrent so as to produce a very rapid series of relatively weak impactsagainst the bit anvil. Whereas, when drilling softer material it wouldbe desirable to provide a slower series of stronger impacts against thebit anvil.

I claim:

1. An electromagnetic tool comprising an elongated tubular body, a toolelement carried at one end of the body for longitudinal reciprocationrelative thereto, said tool element having an anvil head, a solenoidcomprising a reciprocable armature disposed within the tubular body inlongitudinal spaced relation to the said anvil head, a separatetransmission bar slidably disposed between said spaced armature and toolelement, said bar receiving and transmitting impact forces from saidarmature to said tool element, resiliently yieldable means between thebody and armature urging the armature in opposite directionslongitudinally, said solenoid also comprising an electromagnetic coilwithin and secured to the tubular body surrounding said armature, anelectric switch secured to the body and connected electrically to saidcoil, means lying in the path of movement of the armature for openingand closing said switch, and force transmission means between saidarmature and tool element.

2. An electromagnetic tool as defined by claim 1 in which the anvil headprojects upwardly within the tubular body and the tubular body has ashoulder for impacting against the anvil head in a direction opposite tothe forcek the body urging the bit outwardly relative to the body.

6. An electromagnetic tool as defined by claim 1, and a coil springbetween the tool element and body urging the bit outwardly relative tothe body, the maximum force of said spring within its elastic limitbeing substantially equal to the resultant forces acting downwardly onthe tubular body when the body is in a static position resting on thetool element.

7. An electromagnetic tool as defined by claim 1 in which the bodymember is of a diameter adapting it for disposition vertically in a wellopening and the tool element is a drill bit of a diameter not less thanthe diameter of the body member.

8. An electromagnetic tool as dened by claim 7 in which the body memberis of relatively large weight and the drill bit is of relatively smallweight, and means for resiliently supporting the weight of the bodymember on the drill bit.

9. An electromagnetic tool as dened by claim 8 and means for attachingthe body member to a drilling rig.

References Cited UNITED STATES PATENTS 508,262 11/1893 Williams 173-117X 545,149 8/1895 Carpenter 173-117 637,809 11/1899 Meissner 173-117 X1,083,200 12/1913 Diehl 173-117 X 1,341,944 6/ 1920 Study 173-1 172,017,470 10/1935 Miller 173-118 2,402,920 6/ 1946 Seibold 173-1172,827,263 3/1958 Scott et al. 173-117 3,054,464 9/1962 Ondeck 173-117FRED C. MATTERN, JR., Primary Examiner.

HALL C. COE, Assistant Examiner.

1. AN ELECTROMAGNETIC TOOL COMPRISING AN ELONGATED TUBULAR BODY, A TOOLELEMENT CARRIED AT ONE END OF THE BODY FOR LONGITUDINAL RECIPROCATIONRELATIVE THERETO, SAID TOOL ELEMENT HAVING AN ANVIL HEAD, A SOLENOIDCOMPRISING A RECIPROCABLE ARMATURE DISPOSED WITHIN THE TUBULAR BODY INLONGITUDINAL SPACED RELATION TO THE SAID ANVIL HEAD, A SEPARATETRANSMISSION BAR SLIDABLY DISPOSED BETWEEN SAID SPACED ARMATURE AND TOOLELEMENT, SAID BAR RECEIVING AND TRANSMITTING IMPACT FORCES FROM SAIDARMATURE TO SAID TOOL ELEMENT, RESILIENTLY YIELDABLE MEANS BETWEEN TOBODY AND ARMATURE URGING THE ARMATURE IN OPPOSITE DIRECTIONSLONGITUDINALLY, SAID SOLENOID ALSO COMPRISING AN ELECTROMAGNETIC COILWITHIN AND SECURED TO THE TUBULAR BODY SURROUNDING SAID ARMATURE, ANELECTRIC SWITCH SECURED TO THE BODY AND CONNECTED ELECTRICALLY TO SAIDCOIL, MEANS LYING IN THE PATH OF MOVEMENT OF THE ARMATURE FOR OPENINGAND CLOSING SAID SWITCH, AND FORCE TRANSMISSION MEANS BETWEEN SAIDARMATURE AND TOOL ELEMENT.